小兴安岭酸性泥炭土硝化作用的类型及其驱动因子

发布时间：2018-06-29 14:11

本文选题：酸性森林土 + 氨氧化古菌(AOA)　；参考：《应用生态学报》2017年05期

【摘要】：以小兴安岭酸性森林泥炭土为研究对象,通过加入10 mL·L~(-1)乙炔及不同浓度的外源硫酸铵(0、1.2、6.0 mmol N·kg~(-1)进行硝化培养试验,探究酸性泥炭土中硝化作用类型及主要驱动因子.结果表明:无论有无外加氮源,酸性泥炭土均存在较强的矿化作用(0.9~1.4mg N·kg~(-1)·d~(-1),经过2周的培养均发生了硝化作用(0.4~0.6 mgN·kg~(-1)·d~(-1)),且不同浓度硫酸铵处理之间无显著差异;而乙炔处理虽有较强的矿化作用(0.8 mg N·kg~(-1)·d~(-1)),但未发生明显的硝化作用(0 mg N·kg~(-1)·d~(-1)),说明该酸性泥炭土以自养硝化为主,外源无机氮源浓度对硝化作用无显著影响,硝化底物NH_3的主要来源不是外源硫酸铵,更可能来源于土壤中有机氮的矿化.培养0~14 d,无论有无外加氮源,酸性泥炭土氨氧化细菌(AOB)和古菌(AOA)丰度均显著增加,但不同浓度硫酸铵处理间无显著差异,表明外源无机氮浓度对氨氧化微生物的生长无显著促进作用.与不加乙炔的对照相比,乙炔处理AOB和AOA丰度随时间均无显著变化,推测AOA与AOB在该酸性泥炭土的硝化过程中都可能起一定的作用.
[Abstract]:The nitrification types and main driving factors of acid forest peat soil in Xiaoxinganling were studied by adding 10 mL L ~ (-1) acetylene and different concentrations of exogenous ammonium sulfate (0 ~ 1.22 ~ (6) mmol N kg ~ (-1). The results showed that there was strong mineralization (0.9~1.4mg N kg-1 d ~ (-1) in acidic peat with or without nitrogen source, and nitrification (0.4 ~ 0. 6 mg N ~ (-1) d ~ (-1),) occurred after 2 weeks culture, and there was no significant difference among different concentrations of ammonium sulfate. Although acetylene treatment had strong mineralization (0.8 mg N kg-1 d ~ (-1), there was no obvious nitrification (0 mg N kg ~ (-1) d-1), indicated that autotrophic nitrification was the main factor of nitrification in the acidic peat soil, and the concentration of exogenous inorganic nitrogen source had no significant effect on nitrification. The main source of NH3 is not exogenous ammonium sulfate, but more likely from the mineralization of organic nitrogen in soil. The abundance of ammonia-oxidizing bacteria (AOB) and actinomycetes (AOA) in acidic peat soil increased significantly with or without additional nitrogen sources for 14 days, but there was no significant difference between different concentrations of ammonium sulfate treatment. The results showed that the concentration of inorganic nitrogen had no significant effect on the growth of ammonia-oxidized microorganisms. Compared with the control without acetylene, the AOB and AOA abundance of acetylene treatment did not change significantly with time, which suggested that both AOA and AOB might play a certain role in the nitrification process of the acid peat soil.
【作者单位】：西南大学资源环境学院;
【基金】：国家自然科学基金项目(41671232,41271267)资助~~
【分类号】：S714

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